Vial container and closure

ABSTRACT

A plastic vial and closure which is leakproof and especially suited for shipping liquid specimens for medical examination. The vial is provided with screw threads on the outer portion of its neck, a V-shaped recess in the lip, and an upwardly facing, inclined, annular shoulder on the inner wall of the neck. The cap has a cylindrical outer skirt and a shorter, inwardly spaced, inner, cylindrical skirt adapted to be sealingly received against the annular shoulder provided in the wall of the container to make sealing abutment therewith. An annular bead is provided on the cap between the inner and outer skirts and is adapted to seat against the V-shaped recess provided in the lip of the container.

United States Patent [1 1 Davolt 1 May 6,1975

[ VIAL CONTAINER AND CLOSURE [75] Inventor: Ronald L. Davolt, Kansas City, Mo.

[73] Assignee: Ethyl Development Corporation,

Kansas City, Mo.

[22] Filed: May 9, 1973 [21] Appl No.: 358,481

3,741,424 6/1973 Landen 215/43 R Primary ExaminerDonald F. Norton Attorney, Agent, or FirmDonald L. Johnson; John F.

Sieberth; E. Donald Mays [57] ABSTRACT A plastic vial and closure which is leakproof and espe cially suited for shipping liquid specimens for medical examination. The vial is provided with screw threads on the outer portion of its neck, a V-shaped recess in the lip, and an upwardly facing, inclined, annular shoulder on the inner wall of the neck. The cap has a cylindrical outer skirt and a shorter, inwardly spaced, inner, cylindrical skirt adapted to be sealingly received against the annular shoulder provided in the wall of the container to make sealing abutment therewith. An annular bead is provided on the cap between the inner and outer skirts and is adapted to seat against the V- shaped recess provided in the lip of the container.

8 Claims, 9 Drawing Figures FATENTEUHAY ems "1881,62?

SHEET 20F 2 FIG. 6B.

VIAL CONTAINER AND CLOSURE BACKGROUND OF THE INVENTION I. Field of the Invention This invention relates to a plastic vial and closure which provides a leakproof container.

2. Description of the Prior Art For many years there has been a continuing search for improved container-closure combinations which would provide leakproof closures for screw-type and snap-on-type container closures. The problem has been particularly acute in the field of mailing containers, i.e., small vials with screw-top closures which are utilized in the medical trade for mailing liquid specimens. Before the development of plastic containers, small glass vials were used which required packaging in boxes or mailing tubes in order to protect the vial from breakage. Nevertheless, leakage of these glass vial-closure combinations often occurred resulting in damage to associated articles and inability to perform the analysis required on the sample. The advent of plastic containers has, in some part, solved part of the problem in that they are more resistant to breakage; however, the problem of providing an effective seal in plastic containers has continued to plague the trade. One of the more commonly used vial mailing container combinations is described in US. Pat. No. 3,275,180. However, this is a rather costly package to produce and use since it requires an outer vial of special construction which receives an inner vial containing the sample. Rather complicated closing means are utilized in the containers described in the aforementioned patent. Other efforts to solve the aforementioned problem are found in the vial-closure combinations described in US. Pat. No. 2,965,256. These container-closure combinations utilize a single vial with a closure having a groove provided in the inner wall of the cap which enhances the sealing ability of the cap on the container neck. Other art which relates to efforts to improve the leakproofness of container-closure combinations is found in US. Pat. Nos. 3,001,658; 3,360,149; 3,568,87l; 3,707,240; and 3,707,241.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a thermoplastic container-closure combination which is particularly suited for transporting small liquid samples.

It is another object of the present invention to provide a thermoplastic container-closure combination which is substantially leakproof.

It is a still further object of the present invention to provide a thermoplastic container-closure combination which is simple in construction and economical to produce.

It is also another object of the present invention to provide a mailing container which is resistant to breakage.

It is still yet another object of the present invention to provide a thermoplastic container-closure combination wherein the container may be utilized in the medical analytical procedures.

The foregoing objects of the present invention, together with others, are realized in a thermoplastic container-closure which, in combination, comprises a hollow, cylindrical container having a closed end and an open end. The open end provides threads on its outer surface and also provides an upwardly facing, inner shoulder on its inner surface. An annular cap or closure is provided having a top wall and an outer. integral, depending skirt attached to the top wall. The outer skirt provides threads on its inner surface and has an inner, integral, depending skirt attached to the top wall. The lower end of the inner skirt is adapted to seat against the inner shoulder provided in the inner wall of the upper end of the container when the closure is threadedly attached to the container to provide a leakproof seal.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an elevational, perspective view of the container-closure combination of the present invention;

FIG. 2 is an elevational, axial, cross-sectional view of the container of the present invention;

FIG. 3 is a top view of the container of FIG. 2;

FIG. 4 is a cross-sectional, axial, elevational view of the closure of the present invention;

FIG. 5 is an enlarged, sectional view of a portion of the upper open end of the container of FIG. 2;

FIG. 6 is a view similar to FIG. 5 showing a portion of the closure connected to the container;

FIG. 6A is an enlarged, sectional view of a portion of FIG. 6 showing the seating of the annular bead and the cap in the groove in the lip of the container;

FIG. 6B is an enlarged view of a portion of FIG. 6 showing the inner skirt seating on the shoulder provided on the inner wall of the neck of the container; and

FIG. 6C is an enlarged view of a cross section of the inner skirt of the closure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. I, the vial or container, designated generally by the numeral 10, is equipped with a screw-on closure or cap, designated generally by the numeral 11. Referring now to FIG. 2, the container 10 has a generally cylindrical sidewall 12 having an upper, open-ended portion Ba and a lower, closed portion 12b. The upper, open end 12a of the vial is provided on its outer surface with an integral, annular shoulder 13 having a flat, upper surface 13a and a downwardly inclined, lower surface 13b. The outer wall of the upper, open-end portion of the container is also provided with helical threads 14 integrally formed thereon. While the helical threads are shown in the form of modified buttress threads, it is understood that any form of thread may be utilized, and it is not critical in the container of the present invention. As seen more clearly in FIG. 5, the upper end 120 of the container is provided with a recessed shoulder 15 on its inner wall. The shoulder is inclined at an angle a to the enlarged diameter portion of the upper wall 16 in the container neck of from about 20 to about 60, preferably 45. The flat lip surface 17 of the container neck is provided with a V-shaped annular recess 18. The planar walls and 18b of the recess 18 meet at an angle b which may be from about 60 to 120, preferably about 90.

The lower, closed end 12b of the container 10 is provided with an upwardly facing, conical, truncated, bottom wall 19. The bottom wall 19 terminates in an annular, flat portion 20. Integrally formed with the container sidewall 12 and lower portion 12b is a cylindrical skirt section 21 which merges with the upper end of the conical, upwardly facing, bottom wall 19. Referring now to FIG. 4, the cap or closure 11 is provided with a circular, flat, top wall 22 and an integrally formed, depending, outer, cylindrical skirt 23. The inner wall of the cylindrical skirt 23 is provided with integrally formed, helical threads 24 which are adapted to engage the helical threads 14 on the neck of the container 10. The underside of the top wall 22 of the closure I1 is provided with an inner, depending, integral, annular skirt 25 which is spaced inwardly from the outer, cylindrical skirt 23. As seen more clearly in FIG. 6B, the inner skirt 25 is provided with a triangularly shaped end portion 26 which is adapted to seat in the groove provided by the recessed shoulder 15 in the inner wall of the upper end of the container. The triangularly shaped end portion 26 of the skirt is provided with two planar walls 27 and 270, which walls intersect the wall of the cylindrical skirt portion 25 at angles c and d. While these angles c and d may be equal, i.e., at 45, it is preferred that angle be within therange from about 50 to 70 and that angle d be in the range of from about 30 to 55. It is more preferred that angle 0 be 60 and that angle d be 45 for the most effective sealing engagement with the shoulder 15.

Between the outer skirt 23 and inner skirt 25 of the closure, there is provided an integral, annular bead or ridge 29. As seen more clearly in FIG. 6A, the annular ridge 29 is preferably formed in the shape of a hemisphere and is adapted to press against and deform the planar walls 180 and 18b of groove 18 to provide a secondary leakproof seal in the container and closure of the present invention.

Referring now to FIGS. 6 and 6B, when the cap 11 is threadedly engaged tightly with the neck of the container 10, the inner skirt 25 of closure 11 has its lower end 26 received in the inclined recess provided by the shoulder wherein the tip 26 makes deforming contact with the shoulder 15 to cold flow the plastic therearound and provide a leakproof seal between these two surfaces. Additionally, the compressive forces present cause the angular intersection 30 provided by the planar wall 27 and the outside cylindrical wall of the inner skirt 25 to engage the inner wall surface of the upper portion 12a of the container to provide a leakproof sealing engagement with this wall surface by causing a deformation at the point 30 and its contacting area of the wall surface 120. This also provides a leakproof seal for the container and closure. It is preferred that the outside diameter of the inner skirt 25 be slightly less than the enlarged, inside diameter of the wall portion 16 of the container to provide a free sliding fit between these two surfaces to permit easy threading of the cap 11 onto the container 10. Since the primary seal is achieved between the end portion 26 of the skirt 25 and the shoulder 15 on the container, it is not necessary that the outside wall of the skirt 25 closely and frictionally engage the inner wall 16 of the container.

As seen in FIGS. 6 and 6A, the annular bead 29 being hemispherical in shape deforms the planar surfaces 18a and 18b of the groove 18 to provide two secondary sealing surfaces for the container-closure combination. The two primary sealing surfaces are afforded by the skirt lower end 26 seating against the shoulder 15 and the sealing contact made by the annular, angular point 30 of the skirt end seating against the lower portion of the inner wall of the upper portion 12a of the container. Thus, the vial and closure of the present invention provide four separate sealing surfaces which provide a leakproof container-closure combination not found in the prior art containers and vials.

The prime seal existing between the recessed shoulder l5 and the triangularly shaped end of the inner skirt 25 provide a seal far more effective than that found in containers provided by the prior art.

A container and closure was fabricated in accordance with the description given above and the drawings herein, and the container was tested for leakage. The container was filled with water having coloring agents therein in order to detect leakage therefrom. The cap was applied to the container, and torque was applied to 13 pounds to firmly attach the closure to the container. The vial was then inverted in a beaker of water so that the upper half of the container was covered by the water. The container was suspended by means of tape across the beaker containing the water. The beaker and container were then placed on a vacuum pump base and covered with a bell jar to make a good seal. Prior to placing in the bell jar, the container was tapped several times to force all the air between the cap and the vial from the space between the edge of the vial and the shoulder 13. Vacuum was pulled in the vacuum jar until the gauge read 20 inches of mercury or 40 pounds of vacuum. Vacuum was maintained for a considerable period of time, and no colored water could be detected leaking from the vial.

The foregoing test indicates that the container of the present invention is eminently suitable for use as a medical vial for transporting specimens by first-class mail or air mail wherein the vial might be exposed to pressure as low as 20 inches of mercury due to the flight of aircraft at 30,000 to 40,000 feet. The increased pressure inside the container will enhance the seal of the inner skirt against the container neck by pressing this skirt more firmly into contact with the neck.

The container-closure combination of the present invention furnishes other advantages in that it may be sized to exactly accommodate the necessary amount of specimen required for medical laboratory evaluation. Since common urinalysis samples require about 0.5 ounce of fluid, one of the preferred modes of construction is to fabricate the container of the present invention to accommodate about 0.6 ounce of fluid. When so constructed, the container plus a normal fluid sample will have a weight of approximately one ounce which permits the container and its contents to be mailed for the present first-class postage rate for an airmail letter. Thus, the container of the present invention may be readily used as a mailing container and sent first-class airmail at a very low cost. Additionally, it should be noted that the container of the present invention provides a conically tapered bottom portion 19 and a skirt 21 which are sized to fit the receptacle of commonly used centrifuges for centrifuging medical specimens. Thus, the contents of the vial need not be decanted and placed in special centrifuge containers. Additionally, the container and cap of the present invention are adapted for manufacture in a size which permits them to be inserted into conventional outer mailing containers such as those described in US. Pat. No. 3,275,180 whereby the container may form the inner container of such a multiple container combination.

While any suitable material of construction may be used for the present container, it is preferred that it be made from a thermoplastic material, e.g., high, medium, or low density polyethylene, polypropylene, polystyrene, styrene-acrylonitrile polymers, polycarbonate, nylon, acetal polymers or copolymers, polyvinyl chloride polymers or copolymers, and other suitable injection moldable thermoplastics. It is preferred to construct the container of the present invention by injection molding since this provides what is believed to be the lowest cost container at the present time. However, the container could be formed by injection blow molding or other suitable treatment of plastic material. The closure 11 may be made from the plastic materials described hereinbefore or other suitable thermoplastic materials. Additionally, the closure could be made from metal, if desired; however, the plastic materials provide a lower cost and a more suitable material in that they are capable of deformation to provide the novel seal as described hereinbefore.

While there has been described what is at present considered the preferred embodiments of the present invention, it will be apparent to those skilled in the art that various modifications and changes may be made without departing from the essence of the invention. It is intended to cover herein all such modifications as come within the true scope and spirit of the following claims.

What is claimed is:

1. In a thermoplastic container-closure, the combination comprising:

a. a hollow cylindrical container having a closed end and an open end having a lip thereon, said open end providing i. threads on its outer surface, and ii. a cylindrical counterbore on the inner wall thereof extending downwardly from said lip and terminating in an upwardly inclined, inwardly projecting, inner shoulder;

b. an annular closure having a top wall, an outer, in-

tegral, depending skirt attached to said top wall, said outer skirt providing threads on its inner surface, an inner, integral, depending cylindrical skirt attached to said top wall, said inner cylindrical skirt being in sealing engagement with said cylindrical counterbore and the lower end of said inner skirt being seated against said inner shoulder when said closure is threadedly attached to said container.

2. In the thermoplastic container-closure of claim 1 wherein said upwardly inclined inner shoulder intersects said cylindrical counterbore at an acute angle and said lower end of said inner skirt is provided with an end portion in the shape of a triangle.

3. In the thermoplastic container-closure of claim 2 wherein one side of said triangularly shaped end has an angle of about and the other side has an angle of about 45.

4. In the thermoplastic container-closure of claim 2 wherein the end portion of said inner skirt and said inner shoulder are deformed by cold flow at their points of contact to provide a leakproof seal when said closure is fully threaded onto said open end of said container.

5. In the thermoplastic container-closure of claim 1 wherein an annular recess is provided in the lip of the container at its open end and an annular bead is provided on the inner surface of said top wall of said closure, said bead being adapted to seat in said annular recess when said closure is threadedly attached to said container.

6. In the thermoplastic container-closure of claim 4 wherein said recess is triangular in shape and where said bead is hemispherical in shape.

7. In the thermoplastic container-closure of claim 1 wherein an outer, upwardly facing shoulder is provided on the outer surface of said open end of said container below said threads.

8. In the thermoplastic container-closure of claim I wherein the lower end of said container is closed by an integral, conically shaped bottom wall having a diameter at its upper end substantially equal to the inside diameter of the middle portion of said container, said bottom wall being surrounded by a depending, cylindrical, lower skirt section. 

1. In a thermoplastic container-closure, the combination comprising: a. a hollow cylindrical container having a closed end and an open end having a lip thereon, said open end providing i. threads on its outer surface, and ii. a cylindrical counterbore on the inner wall thereof extending downwardly from said lip and terminating in an upwardly inclined, inwardly projecting, inner shoulder; b. an annular closure having a top wall, an outer, integral, depending skirt attached to said top wall, said outer skirt providing threads on its inner surface, an inner, integral, depending cylindrical skirt attached to said top wall, said inner cylindrical skirt being in sealing engagement with said cylindrical counterbore and the lower end of said inner skirt being seated against said inner shoulder when said closure is threadedly attached to said container.
 2. In the thermoplastic container-closure of claim 1 wherein said upwardly inclined inner shoulder intersects said cylindrical counterbore at an acute angle and said lower end of said inner skirt is provided with an end portion in the shape of a triangle.
 3. In the thermoplastic container-closure of claim 2 wherein one side of said triangularly shaped end has an angle of about 60* and the other side has an angle of about 45*.
 4. In the thermoplastic container-closure of claim 2 wherein the end portion of said inner skirt and said inner shoulder are deformed by cold flow at their points of contact to provide a leakproof seal when said closure is fully threaded onto said open end of said container.
 5. In the thermoplastic container-closure of claim 1 wherein an annular recess is provided in the lip of the container at its open end and an annular bead is provided on the inner surface of said top wall of said closure, said bead being adapted to seat in said annular recess when said closure is threadedly attached to said container.
 6. In the thermoplastic container-closure of claim 4 wherein said recess is triangular in shape and where said bead is hemispherical in shape.
 7. In the thermoplastic container-closure of claim 1 wherein an outer, upwardly facing shoulder is provided on the outer surface of said open end of said container below said threads.
 8. In the thermoplastic container-closure of claim 1 wherein the lower end of said container is closed by an integral, conically shaped bottom wall having a diameter at its upper end substantially equal to the inside diameter of the middle portion of said container, said bottom wall being surrounded by a depending, cylindrical, lower skirt section. 